Vice-versa would also be nice. Indeed, it would be good if the two were wholly linked, such that any changes made on one (JIRA or BitBucket Issue Tracker) are also made on the other (where both platforms support the action, of course), including creation, comments, status transitions, and so forth.

At that point, though, should we instead have this filed under the JIRA DVCS Connector Plugin issue tracker? Because it might actually be possible to handle the full integration there, thanks to the BitBucket REST API.